The hard X-ray source 4U 2206+54 is a peculiar high mass X-ray binary with a main-sequence donor star .
Recent X-ray observations suggested that the compact object in 4U 2206+54 may be a neutron star .
The X-ray emission comes from the accretion of stellar winds from the massive donor stars , and variability of luminosity may be due to the changes of its orbit phase .
To further reveal the nature of compact object , we studied 4U 2206+54 with INTEGRAL/IBIS observations in two years , and found that in most time , 4U 2206+54 undergone a quiescent state and sometime an active state .
In the quiescent state the spectrum can be fitted by a power-law model of \Gamma \sim 2.1 with a hard X-ray luminosity of \sim 5 \times 10 ^ { 34 } erg s ^ { -1 } ( 20– 100 keV ) .
While in the active state , the 20– 100 keV hard X-ray luminosity reaches \sim 2 \times 10 ^ { 35 } erg s ^ { -1 } and the spectrum is fitted by a thermal bremmstrahlung model of kT \sim 43 keV plus two cyclotron absorption lines at \sim 30 and 60 keV .
Then we derived a magnetic field of 3.3 \times 10 ^ { 12 } G for the compact object in 4U 2206+54 .
During the active state , we found a pulsation period of \sim 5400 s in the light curve of 4U 2206+54 .
So the compact object in 4U 2206+54 should be a magnetic neutron star with a slow pulsation .
Cyclotron absorption lines detected in the active state and non-detection in the quiescent state suggested that two different accretion states have possible different hard X-ray emission regions : surface of neutron star in the active state ; the magnetic-accretion pressure equivalent point in the quiescent state .
The re-analysis of the RXTE/ASM light curve found the modulation periods at \sim 9.56 days and 19.11 days , and the orbit period of 4U 2206+54 should be 19.11 days .